How Would You Know?
by Lothiriel84
Summary: Mycroft shakes his head. "Let him talk. People do very little else." - Sherlock struggling with his own sexuality, or lack thereof. Spoilers up to 3x03.
1. Chapter 1

Sherlock is ten when the neighbours' kid asks him what's wrong with his brother. He feels insulted on Mycroft's behalf; nothing could ever be wrong about his big brother, he's the smartest person Sherlock knows, and his role model too.

"Ben says he saw him kissing a boy. Now that's disgusting."

"You're disgusting," Sherlock seethes, kicking the moron on his shin.

When he gets home with a black eye and a split lip his brother raises a questioning eyebrow, then sneaks him into his room without their parents even noticing. Mycroft's hands are gentle as he tends to his wounds, and Sherlock finds the courage to ask the question that's dancing on the tip of his tongue.

"Boys are supposed to like girls, aren't they?"

"There's no such thing as 'supposed to', Sherlock," his brother explains patiently. "Some boys like girls, while others like boys better. And there are some who like both girls and boys alike."

"Why?"

"Dunno. That's just the way it is."

He suspects that Mycroft actually knows – he knows everything after all – but it's probably one of those things only grown-ups are entitled to talk about.

"Is it okay to like boys then? Tim says it's disgusting."

"Tim's just a kid, and a dull one too. Is that how you got yourself beaten up?"

"He said some horrible things about you. He said –"

Mycroft shakes his head. "Let him talk. People do very little else."

"How is it like – kissing someone, I mean?"

"Satisfactory. It's the endorphins, you know."

"What are endorphins?"

His brother spends the rest of the afternoon teaching him everything he needs to know about neurotransmitters and the chemistry that makes them work. Sherlock drinks in all the fascinating information, and the incident with the neighbours' kid is quickly forgotten.

xxx

He's seventeen when he starts wondering what's wrong with himself. His classmates are always boasting about their latest conquest, while he's only interested in chemistry books and detective stories.

In the end he decides to give it a try, treating the whole thing as he would do with one of his experiments. Girls are probably the easiest place to start, there's one that has been pestering him to go out with her for the better part of the spring term.

Sherlock is not impressed in the slightest when she threads her fingers through his hair, nor when she meets his lips for what he presumes would constitute a kiss. He tries to recall everything he knows about the chemistry of love, but fails miserably.

This is just stupid; and wrong, so very wrong. He catches her wrist before her hand can reach its intended destination, pulls away from her embrace.

"I'm sorry," he states flatly, ignoring the flash of disappointment in her eyes.

Girls aren't really his area, that much is apparent; he supposes that means he's gay, just like his brother.

It doesn't take him long to find a suitable subject to test his theory on. Victor is a nice guy, and he seems quite delighted when Sherlock puts on a show of being interested.

His lips are more demanding than Violet's, and yet he finds himself just as unresponsive to the other's touch as on that previous occasion. This isn't working, he has no idea how it's supposed to work in the first place.

He feels like an idiot when he excuses himself and hastily walks away. That night he lies awake in his bed, thinking back to the conversation he had with his brother some seven years before.

Mycroft notices there's something off about him when he gets home for the weekend, promptly demands to have a word with his little brother.

"You can't order me around, Myc. I'm not a child anymore."

"Apparently not. You're still sulking just like a kid would do."

He slumps into his brother's favourite chair, turns a weary look out of the window. "You were wrong, you know."

"I beg your pardon?"

"You said that one can like either boys or girls, or both. Well, I don't."

They stare at each other for a moment, then Mycroft slowly shakes his head. "You were ten, Sherlock. I wasn't particularly keen on discussing the whole spectrum of human sexuality with a brat."

He pauses, biting at his lower lip in a vain attempt to conceal his vulnerability. "Are you now?"

"There's nothing wrong with the lack of sexual attraction. It just means you're asexual."

"People don't tend to see it that way."

His brother sighs. "Ignorant people, maybe. You are what you are, Sherlock; no one else is entitled to tell you otherwise."

Silence stretches between them, until he's the one who eventually breaks it. "Thank you, I guess?"

"You're welcome, brother mine," Mycroft smirks, and he almost thinks he misses the old camaraderie they used to share when they were kids.


	2. Chapter 2

He's thirty-four now, and he thinks he has figured out the basics facts about romance and intimacy. Most of times he can easily deduce when a person is attracted to another, it boils down to tell-tale signs such as elevated pulse and dilated pupils.

What still eludes him is the reason behind all this. He supposes ordinary people find it exciting, just as he's thrilled by a mystery or a challenge; he's not sure why they even bother when it messes up with their rationality, but then most people's brains are quite boring if compared to his own.

When he meets Molly Hooper he feels a bit uneasy about her blatant crush for him. She's a smart woman, and a competent pathologist too; he really can't understand why she should make such a fool of herself for someone that barely notices her, though he uses the knowledge to his advantage on occasion.

He's fond of her, after his own fashion. She's generous and compassionate, and he knows he can trust her completely. If only she realized that he's not interested in anything but being on friendly terms, then things would be less awkward whenever they happen to meet.

xxx

Sherlock likes John Watson. He really does. It doesn't matter that John doesn't get his meaning when he tells him he's married to his work.

"It's all fine," that's what his friend says, and he decides to take it as an approval of sorts.

He enjoys bantering with John, ordering him about until the former army doctor eventually snaps at him. Mycroft says they are a couple in their odd way, and he supposes his brother might be right after all.

Except that he has no desire whatsoever to engage in any of the activities that are a distinctive trait of ordinary couples. He doesn't want to kiss John, nor is he looking forward to sharing a bed with him; all he craves is solving crimes together, and his friend's admiring – and slightly exasperated – stare following him all the time.

Still he's only too aware that, being an heterosexual male, John's needs are quite different than his own. It's only a matter of time before his friend decides to settle down with a woman and a family of his own.

xxx

"Sex doesn't alarm me," he argues when his brother not-so-subtly implies otherwise.

Mycroft only gives him a condescending look. "How would you know?"

That's completely unfair of him, though Sherlock has to concede it might be payback for his previous act of bravado; the incarnation of the British government can't afford to have his little brother showing up in Buckingham Palace wearing nothing but a sheet.

He's not afraid of the Woman, nor is he liable to be seduced by the infamous dominatrix. However, he's not entirely prepared for the kind of seduction she has especially reserved for him.

It has nothing to do with sexual attraction; she has brains, and he happens to have a weak spot when it comes to showing off his cleverness. That's the only thing he takes pleasure in, impressing everybody around him with his deductive skills.

And he does impress her, though not in the way either of them was expecting.

In the end he decides he can't let a mind like hers go wasted, saves her from certain death all the while pulling wool over his brother's eyes. That night she slaps him until her hands are sore, because that's what she likes and he's a glutton for punishment.

It's good to be able to feel something at last, even if it's just pain.

xxx

There's a woman in his flat, and he feels like the very thought is suffocating him. Janine may be a passable distraction now that John is not around, but her constant need for attentions is wearing him out.

He can endure kissing her for a reasonable amount of time, even tolerate her closeness up to a point. Intercourse, on the other hand, is completely out of question; there's only so far he can go after all.

It's such a relief when the ruse is finally over, no matter that he hasn't actually achieved what he set out for. Mycroft chooses to tease him about his supposed change of heart, though he knows well enough that his little brother has nothing to partake with the unlikely stories Janine sold to the newspapers.

Sherlock shudders at the unwelcome memories, thinks back to the chaste kiss he planted on Molly's cheek upon his return – and the warm hug John gave him after he delivered his pathetic excuse for a best man's speech. Friendship is the one sentiment that's familiar to him, the only thing he's longing for.

That's why he pulls the trigger at last, even if he's well aware that it will probably break his brother's heart.


End file.
